Ubuntu/ISPConfig/Postfix/Mailman Installation Issues

As far as I know, Ubuntu, Apache, ISPConfig, and Postfix are running ok. I verified this by:
- ssh'ing into the ubuntu server
- logging into the ISPConfig pages on the server using a browser
- sending/receiving email through the Postfix server

- If I go into my ISPConfig setup via https://myhostname:81, I log in fine
- If I log into SSH via myhostname, it works fine
- When I try to log into my mailman install, via http://myhostname.com/cgi-bin/mailman/admin, there is a 404 error. HOWEVER, if I log into my mailman install, via http://ipaddress/cgi-bin/mailman/admin/, I can get to it fine. However, when I click on a link to add a new list, for example, the link is to the FQDN version of the url. It does not work. If I just change the domain name to the ip address, any page within mailman works.

It's weird because I would expect ALL references to myhostname.com to not work, if there was an issue with DNS. However, it looks like it's only when I'm trying to access the mailman install.

I did create a web site with ISPConfig.
One thing that may be confusing the server is this:

The server is on IP 10.10.1.1 (example)
The FQDN of the server is www.mydomain.com (example)

I am only going to host 1 site on this server.
Therefore, I want the site to be:
10.10.1.1 and www.mydomain.com

There are a couple other things that are interesting.

1. The SSL certificate seems to be configured wrong. I say this because when I type into a browser https://www.mydomain.com:81, the browser asks if I am sure I want to accept this certificate because it may be incorrect. When I look into the details of the certificate, it says the certificate is for:
www2.mydomain.com, not www.mydomain.com

2. When I type in the ipaddress of the server/site into a browser, a welcome page is displayed, but it says that it is a shared IP.

1. The SSL certificate seems to be configured wrong. I say this because when I type into a browser https://www.mydomain.com:81, the browser asks if I am sure I want to accept this certificate because it may be incorrect. When I look into the details of the certificate, it says the certificate is for:
www2.mydomain.com, not www.mydomain.com